gfsview binary package in Ubuntu Focal amd64

 Gerris is a system for the solution of the partial differential
 equations describing fluid flow.
 .
 GfsView displays the results of 2D and 3D Gerris simulations.
 A brief summary of its main features:
 .
    * Scalar and vector cross-sections.
    * Isosurfaces.
    * Streamlines.
    * User-defined functions.
    * Fast adaptive display (using the multiresolution data
      representation of Gerris).
    * Scriptable.
    * Offline image generation.
    * Quality PostScript, PDF and bitmap outputs.

Source package